There are many situations in the design of material handling equipment, such as conveyors, work benches, work stations, carts, feed stations, or the like in which it is desirable to be able to use ball-type anti-friction elements to provide for change of direction of an object moving along the conveyor or to provide a table on which the object can be moved and rotated to a desired orientation. Such elements have been provided in the past only as part of a complex mechanism that was especially designed for a particular application. Such mechanisms have been expensive and tend to interfere with the operation, for instance, of the drive belt of a roller-type conveyor. Furthermore, they usually extended vertically to a considerable extent, thus interfering, for instance, with their use as part of a table or, as has been stated previously, interfering with the mechanism underlying a roller-type conveyor or the legs of personnel seated before a table. Many of these mechanisms involve exposed moving elements which could be dangerous to personnel working around the conveyor work benches, etc. These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide anti-friction elements for use in designing equipment of various kinds and capable of many applications.
Another object of this invention is the provision of a friction element which permits the construction or retro-fitting of inexpensive work tables, benches, or conveyors or transfer tables.
A further object of the present invention is the provision of anti-friction elements which are short in the vertical direction, so that they do not interfere with other mechanisms in the vicinity, such as the drive mechanisms for a conveyor or with the legs of personnel seated before a table.
It is another object of the instant invention to provide an anti-friction element which can be readily fabricated from readily-available materials, which is simple in construction, and which is capable of a long life of useful service with a minimum of maintenance.
A still further object of the invention is the provision of an anti-friction element having a retractable ball which is not dangerous to operating personnel and which can be maintained substantially free of dust and other damaging particles.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.